The ancient stone city of Machu Picchu perched on a mountain ridge above the clouds, surrounded by green peaks
VOL 3: LOST WORLDS VERDICT: STILL DEBATED

The Cloud City

The Inca Built a Perfect City in the Sky — Then Abandoned It Without a Word

Built ~1420
Abandoned ~1530s
Difficulty Standard
Chapters 9
INVESTIGATE

In 1911, an American history professor climbed through dense jungle in Peru and emerged above the clouds to find an ancient city — about 200 stone buildings, sixteen fountains, and walls so perfectly fitted that a knife blade cannot pass between the stones. The Inca built it around 1450 with no wheels, no iron tools, and no mortar.

Then, sometime in the 1530s, they walked away. The Spanish conquered their entire empire but never found this place. Local farmers always knew it was there — one visited nine years before the man who claimed to have "discovered" it.

After 600 years, the walls still stand, the fountains still carry water, and the stones still dance in earthquakes and settle back into place.

The Mystery

~600 Years Old

Emperor Pachacuti ordered the construction of Machu Picchu around 1420–1450. About 750 people lived there — royals, priests, servants, and workers. It functioned for roughly a century before being abandoned.

Altitude

2,430 m

Nearly 1.5 miles above sea level — literally above the clouds.

Structures

~200

Temples, houses, fountains, and terraces — all built without mortar.

Fountains

16

All fed from a single mountain spring through a 749-metre canal.

The Evidence

The Intihuatana stone, a carved granite pillar on a stepped platform
SACRED STONE

The Intihuatana

A carved granite pillar tilted 13 degrees north, used to track solstices and equinoxes. One of the only Intihuatana stones to survive — because the Spanish, who destroyed all others, never found this city.

Panoramic view of Machu Picchu's terraces and stone buildings
THE WALLS

Dancing Stones

The walls were built without mortar using ashlar masonry — stones cut so precisely a knife blade cannot fit between them. During earthquakes, the stones shift and sway, then settle perfectly back into place.

The Temple of the Sun with its curved walls and precisely aligned windows
THE TEMPLE

The Temple of the Sun

A semi-circular tower with windows precisely aligned to the solstices. On specific days, sunlight enters and strikes a ceremonial stone at exactly the right angle — proof of advanced astronomical knowledge.

From Empire to Jungle to World Wonder

~1438

Pachacuti Takes Power

Cusi Yupanqui becomes the 9th Sapa Inca, takes the name Pachacuti ("Earth-Shaker"), and begins transforming a small kingdom into the largest empire in pre-Columbian America.

~1420–1450

The Cloud City Built

Pachacuti orders the construction of Machu Picchu as a royal estate on a ridge between two peaks. Workers quarry stone from the mountain itself. About 750 people will call it home.

~1530s

Abandoned

Disease, civil war, and the collapse of the Inca Empire drive the inhabitants away. The jungle reclaims the city within a generation. The Spanish, just 80 km away, never find it.

1902

Lizárraga Visits

Peruvian farmer Agustín Lizárraga visits the ruins and writes his name and date on the Temple of the Three Windows. He is the first known outsider to visit — nine years before Bingham.

JUL 1911

Bingham Arrives

Hiram Bingham III, guided by local farmer Melchor Arteaga, climbs to the ruins. He finds two Quechua farmers already living there — and Lizárraga's inscription on the wall.

2011–12

Artifacts Returned

After a decades-long dispute, Yale University returns thousands of artefacts to Peru. They are now displayed at the Casa Concha museum in Cusco.

The People in This Story

The Builder

Pachacuti

The 9th Sapa Inca who transformed a small kingdom into the largest empire in pre-Columbian America. Most archaeologists believe he commissioned Machu Picchu as his private royal estate around 1420–1450.

The Forgotten Finder

Agustín Lizárraga

A Peruvian farmer who visited the ruins in 1902 — nine years before Bingham. He left his name on the wall. He drowned in 1912 and was erased from the story for a century.

The Fame-Maker

Hiram Bingham III

A Yale history professor who brought Machu Picchu to the world's attention in 1911. He misidentified the site as Vilcabamba and shipped thousands of artefacts to Yale — where they stayed for nearly 100 years.

Modern visitors walking along the terraces of Machu Picchu with mountains behind
Machu Picchu today — a UNESCO World Heritage Site and one of the New Seven Wonders of the World. Over 1.5 million people visit every year.

The Question That Remains

The walls still stand. The fountains still run. The stones still dance in earthquakes. But the Inca left no written records — so every theory is built from reading the ruins.

Was Machu Picchu a palace, a temple, an observatory — or something nobody has thought of yet? And who deserves to be called its discoverer — the man who told the world, the farmer who got there first, or the people who never left?

Read the full book to investigate every piece of evidence — then decide for yourself.

The Cloud City book cover

Get the Full Book

The complete Machu Picchu mystery. 9 chapters of evidence, theories, and a question only you can answer.

9 Chapters Ages 8-12 DRM-free EPUB

Part of the Lost Worlds Volume

Sunken cities, impossible structures, and civilisations that vanished before history began. What did the ancient world know that we have forgotten?

See all books in this volume →